Performance analysis of solar energy(PV/T) and/or wind energy assisted heat pump systems

Today, the increasing energy demand and the environmental impacts of fossil fuels have further increased the importance of renewable energy sources. The energy obtained from renewable energy sources such as solar and wind also plays an important role in combating climate change by reducing carbon emissions. In this study, three provinces with different solar radiation and wind speed conditions were selected. For the selected provinces, energy and exergy analyses of air source heat pump systems and photovoltaic-thermal (PV/T) assisted water source heat pump systems were carried out using four different refrigerants. The wind turbine's contribution to meeting the compressor demand of the air source heat pump system and the contribution rate of the PV/T collector in meeting the compressor demand in the PV/T assisted water source heat pump system were evaluated. In addition, a scenario in which both wind and PV/T supported systems are used in a hybrid manner was also evaluated, and the payback periods of these systems were calculated. Within the scope of the study, exergy losses in heat pump units depending on outdoor air temperature and water inlet temperature were also analyzed. According to the calculations, an evaluation was made as to which refrigerant performed better in which province and which system was more applicable. According to the results obtained, the PV/T assisted water source heat pump system using R290 refrigerant showed the best performance in all provinces, provided that the required collector area was available. In the provinces of Çanakkale and İzmir, the refrigerant with the highest coefficient of performance (COP) and the lowest compressor power was R290, while in the province of Van, R32 refrigerant stood out in terms of these values. When exergy analyses were examined; among the refrigerants, R410a showed average performance, while R32 showed prominent performance especially in the compressor and expansion valve, R1234yf in the condenser, and R290 showed a balanced and successful performance in all units, although not the highest. In air source and PV/T assisted water source heat pump systems, it was observed that the performance of R1234yf and R290 refrigerants improved as the outdoor air temperature and water inlet temperature increased. Although R32 and R290 refrigerants gave similar results in terms of COP and compressor power, it was determined that R32 refrigerant was better in cold outdoor air conditions, while R290 refrigerant performed better in hot and mild climate conditions. Thanks to the high wind potential in Çanakkale, it was seen that the wind-assisted air source heat pump system more than met the compressor power, and similarly, the PV/T assisted water source heat pump system also met this power. It was observed that the hybrid system, in which both renewable sources were integrated, was also successful in meeting the demand. In terms of payback period, the PV/T assisted water source heat pump system was found to be more advantageous, however, considering the continuity of energy and the sale of the generated electricity to the distribution company, it was also seen that the hybrid system using both wind and solar together was economically viable. In the province of Van, due to the low wind potential and high solar radiation, the PV/T assisted water source heat pump system was determined to be a more suitable option. In the province of İzmir, due to the insufficient wind potential and high investment costs, it was concluded that the hybrid system is not applicable and that only the PV/T assisted water source heat pump system is appropriate.